Limb cancer treatments in pets have come a long way since we founded the Tripawds community in 2006. That’s why we’re so excited to bring you this episode of Tripawd Talk Radio featuring Dr. Kristen Couto, a board-certified veterinary oncologist from Bend, Oregon.
Hope on the Horizon: Dr. Couto Talks Tumors, Treatments & Tripawd Dogs Beating Cancer!
Tune in as Dr. Couto explains what kinds of limb cancer treatment immunotherapy breakthroughs are available for dogs who lost a leg to cancer. From promising new vaccines to mast cell cancer treatment options that just might extend survival time and improve quality of life.
And she does it all in pet parent speak that makes it easy to understand. Listen so you can have a great conversation with your vet team about how to care for your Tripawd through cancer therapy and beyond!
So whether you’re just starting your journey or exploring treatment paths after amputation, this Tripawd Talk episode is filled with must-know insights and real hope for your pet’s future.
Subscribe to Tripawd Talk Radio in your podcast player app!
Meet Our Special Guest: Dr. Kristen Couto: A Legacy in Veterinary Oncology
Dr. Kristen Couto is Bend, Oregon’s first board-certified veterinary oncologist. She grew up immersed in the world of animal cancer care as the daughter of renowned Greyhound health expert Dr. Guillermo Couto.
Inspired by her family’s legacy, Kristen followed a similar path and became board-certified in oncology after training at top institutions including The Ohio State University, NC State, and UC Davis. Today, she works at the Veterinary Referral Center of Central Oregon (VRCCO), helping pet parents navigate the emotional and clinical journey of cancer treatment for their beloved animals.
Watch Tripawd Talk Episode # 129.
RESOURCES
- The Yale Vaccine Cancer Treatment: A Dog of Science Field Report
- Torigen Immunotherapy Vaccine: Hope for Pets with Cancer Podcast
- Dogs Beat Osteosarcoma Odds with ELIAS Cancer Immunotherapy Treatment
- Stelfonta: A Canine Mast Cell Cancer Treatment Breakthrough!
- Gilvetmab: An innovative option for treating cancer
Read our show transcript below!
The Latest Limb Cancer Immunotherapy Treatments for Tripawd Dogs, with Dr. Kristen Couto, Tripawd Talk Episode #129
TRIPAWDS: Hi, Dr. Couto, it’s so nice to meet you. Thank you for being here on Tripawd Talk!
DR. COUTO: Of course, my pleasure to join.
TRIPAWDS: It is a real treat to get to talk to you. I have been a fan of your father’s work for so long. We did a keynote speech for a Greyhounds conference and the Greyhounds people are the ones who told us about your dad’s work. I’ve followed all of the great things he does for the Greyhound community all these years. Then one of our members mentioned that you were working out in Bend, Oregon, and I said, “Wow! I had no idea that he had a daughter who was in the field. I came to find out you actually have a twin brother who’s also in the field!”
DR. COUTO: It’s an interesting family dynamic. I’ll tell you that.
TRIPAWDS: Yes, tell me about it, I mean, was it always going to be a given that you were going to study oncology? And your brother, too? How did that happen?
Family Roots and Finding Her Own Path in Oncology
DR. COUTO: I always knew I wanted to be a vet from the early days. I really had no idea I was going to want to go down the path of oncology until probably I was a fourth year vet student, truly immersed and engaged in the actual medicine. I was just drawn to that. I don’t know if there’s a DNA component to that or not, but I was kind of drawn to it.
I really thought about doing other things because I didn’t necessarily just want to go down that same path. But nothing else really spoke to me like oncology does so I ended up deciding to go for an internship and residency, and then, you know, here we are.
00:02:55.850 –> 00:03:19.180
DR. COUTO: And then my brother, he definitely did not always want to be a vet, was not going to be a vet from the beginning. He had a lot of other interests when we were in college, but then did decide a little bit later that he wanted to go to vet school. Also from the beginning, I think knew if he was going to go to vet school, he wanted to be an oncologist.
00:03:19.220 –> 00:03:34.333
DR. COUTO: Now we both are oncologists in the Pacific Northwest, three-and-a-half hours from each other. It’s funny, my brother and I actually share a lot of cases, because there’s a lot of people that travel back and forth between Portland area and Bend.
00:03:36.390 –> 00:03:42.600
TRIPAWDS: Oh, how neat! I imagine that your family get togethers are all about the dogs and cats
00:03:42.600 –> 00:03:54.329
DR. COUTO: There’s a lot of really rowdy animals that are in our household. And yes, a lot of veterinary talk. My mom is not a veterinarian, but she basically is because she’s been living with my dad for ages, and is very close with my brother and I. So yes, it’s a very tight knit family, and there is a lot of that talk.
00:04:07.110 –> 00:04:24.580
TRIPAWDS: That’s pretty cool. Three vets, three oncologists. And it’s such an exciting time to be in the field. I mean, so many things have changed since Tripawds started in 2006. We’ve seen the treatments evolve, and for our community, it’s always about limb cancers. And I wanted to talk to you today because I would just really like to know what are some of the new developments that are out there?
We get a lot of people asking about vaccines. What do we get? Do we talk to our vet about it before surgery? Can we talk about it after surgery? What are the options for the latest treatments? And I know it’s a big topic, but if there’s one in particular that you want to talk about first, we can do that.
The Importance of Timing: Why Early Consultation Matters (Before Amputation Surgery)
DR. COUTO: I would say that I love to have the conversation personally, when able, prior to any type of concrete decision making for treatment, because with immunotherapy options that we have available, you kind of have to start (talking about it) from the beginning. Because some of them will actually utilize the tumor tissue itself to be able to make an autologous vaccine. We have to know about that ahead of time, so that we can process the tissues correctly.
00:05:38.070 –> 00:05:57.620
DR. COUTO: There is one vaccine that I would say is on the market that does not have to be known about right away, because it’s not an autologous vaccine. But the other two that are currently available, you really have to know about it ahead of time before an amputation to be able to go down that path for treatment.
The Yale (EGFR) Vaccine
00:05:57.810 –> 00:06:10.799
DR. COUTO: The big three that I currently consider for any of my patients, the first new immunotherapy option would be an EGFR vaccine, which is currently only offered at certain facilities that are working with the people that started the vaccine. And this basically is targeting EGFR mutations over expression that are present in about forty percent of canine osteosarcomas, from what we can tell.
This is a treatment that can be utilized following amputation. It can be utilized concurrently with chemotherapy. It could (also) be utilized after chemotherapy, and there’s no preparation that would be required, other than finding a facility that you are able to travel to, that has access to the vaccine. It is not yet a commercially available vaccine but it is something that you can often find if you look for it, or if you ask your treating oncologist where the closest facility could be. A lot of them will kind of know what their options are close by
00:07:09.830 –> 00:07:32.769
DR. COUTO: Here in Bend, we have two options, I do not have it here unfortunately. I’ve tried very hard to get access to it, but not quite yet. Washington State University does have access to it, and there is a clinic up in Seattle that also has access to it. We have numerous pet parents in Bend that travel to either of those locations for the EGFR vaccine.
The Torigen Vaccine
00:07:33.240 –> 00:07:56.139
DR. COUTO: The other two like I mentioned, are ones that you really need to know about ahead of amputation. The first one would be the Torigen autologous vaccine series. Torigen is not by any means specific to osteosarcoma, whereas the EGFR vaccine is slightly more specific to osteosarcoma, there’s a few other types of cancer that it has been that it is currently being studied for.
But Torigen is something that can be utilized for literally any type of cancer, it is simply an autologous cancer vaccine. So you take the cancer tissue, it is processed at a lab and then (for simplicity), basically just reinjected into the body to try to stimulate the pet’s immune system to try to target the cancer cells themselves. But the processing required is special, because there cannot be any formalin that touches the sample that will then be processed into the vaccine.
And typically anytime we’re taking surgical biopsies or removing masses we will place them in formalin for fixation, for histopathology to gain a definitive diagnosis. If you do that, and you don’t save any of the tissue fresh, you do not have access to the Torigen vaccine.
Collaborate with your veterinary team before choosing a path
00:09:06.600 –> 00:09:23.020
DR. COUTO: And if they’re interested in trying to kind of, you know, push the bubble and try to do more treatment than just the conventional amputation and chemotherapy, know that there are options out there. Talk to someone about those options before making a finalized path.
I think one of the things that’s easier said than done in certain communities and our community here, you know, I have fairly good ability to get pets in quickly when I need to, it’s a fairly small referring community. We’re in the middle of nowhere in Central Oregon, so there’s not that big of a surrounding location. But it could be more difficult in city regions where sometimes you have to wait four to six weeks to get into an oncologist.
But there’s a lot of information available online. And many people would be able to at least look into this information and talk to their family vet. If the family vet is doing the amputation, and at least having the family vet process the sample in a way that would leave that open as an option.
00:10:07.920 –> 00:10:13.669
TRIPAWDS: That’s good to know, so that you wouldn’t have to necessarily have the surgery at a specialty clinic?
00:10:13.670 –> 00:10:43.330
DR. COUTO: No, you do not. And if anybody ever has questions about that, I work closely with the Torigen company. I’ve been using their product for a while, and I’m always happy to answer questions. I have vets that call me, “Just how do you even process this? What do you even do to try to get it there? And all of that information, I’m happy to review it with people. Many oncologists know about it, and the company has great customer service. They will answer questions like that all the time.
00:10:43.690 –> 00:10:58.599
TRIPAWDS: We do have a previous podcast with the Torigen folks so I’ll be sure to put that in the show notes, so that people can reference that. It was a while ago, though, so that’s why I wanted to talk to you today.
Can you explain, what does autologous mean?
00:10:58.840 –> 00:11:04.029
DR. COUTO: Yeah! Autologous mainly means that we’re basically taking something from the self, and we’re re-injecting it into the self. We use this term a lot when we’re talking about, for instance, bone marrow transplants or kidney transplants and things like that.
Because sometimes you’re going to want to use self-to-self, sometimes you’re going to want to use a related individual-to-the-individual. And then other times, you know, they’re talking about (not that this is what this is about) but pig kidneys going into humans and things like that. And so that would obviously not be autologous.
00:11:35.190 –> 00:11:44.239
TRIPAWDS: Got it. Thank you for explaining that.
The ELIAS Adaptive T-Cell Transfer Protocol
00:11:44.240 –> 00:12:00.089
DR. COUTO: And then there is one more, and I think it’s important to mention, because this is probably the one that I, in my opinion, has the most presence out there. There is the ELIAS immunotherapy option, which is an adaptive T-cell transfer.
The ELIAS protocol. I’m going to be honest, I have not utilized it myself. I do not have apheresis at my clinic, or in Bend in general. Yet we are actually getting apheresis at our clinic soon. We’re looking into whether that’s going to be an option for us to be able to start offering this treatment.
But the ELIAS vaccine or immunotherapy protocol is also something you very much need to know about ahead of time. There is no path to this treatment unless there is very specific processing that is done with the limb. At the time of initial amputation it has to be sent directly to ELIAS for processing into another autologous vaccine.
And then the autologous vaccination protocol is given following amputation. There is a protocol where we do leukapheresis or actually remove white blood cells from the pet’s body. We process those white blood cells. And we’re kind of trying to specifically make and promote these Killer T-cells that are then re-injected into the pet’s body to try to specifically target the individual’s cancer cells.
00:13:14.350 –> 00:13:28.080
DR. COUTO: Then they utilize an interleukin treatment to try to stimulate the immune system following the actual adaptive T-cell transfer. It is a very long treatment protocol. It lasts several weeks, which isn’t dissimilar to chemotherapy. The most conventional chemotherapy protocols out there use four-to-six doses of carboplatin. This is something that currently has been studied mainly just with amputation alone, it’s just amputation. And then the adaptive T-cell transfer. My understanding is that there are people looking into combining it with chemotherapy to try to see if we can get even better survival time.
Hope for the Future: Promising Results and Practical Advice
00:13:53.100 –> 00:14:06.329
DR. COUTO: I think the big picture with ELIAS is that it does end up being, from what I can understand, a little bit more expensive than the traditional path of amputation and chemotherapy. But with both the EGFR vaccine and the ELIAS immunotherapy, at least initial studies are reporting slightly improved survival times, as compared to what is called “Standard of Care,” which would be amputation with four-to-six doses of carboplatin. Those survival times are still around the 12 to 14 month mark. That’s a median, so fifty percent of dogs do better, fifty percent of dogs do worse. ELIAS is hopeful that, when it’s combined with chemotherapy, that might be able to go up.
00:14:43.840 –> 00:15:12.160
DR. COUTO: With any of these immunotherapy options, what is more likely is that there is just a subset of pets that will live much longer than the average. And that’s what we’re likely seeing with these immunotherapy options.
Not necessarily that the median is going to change significantly, but that there will be a subset of dogs that do incredibly well with the treatment protocol and that live much longer than, for all intents and purposes, they should have.
00:15:13.210 –> 00:15:38.259
DR. COUTO: And Torigen,.there’s not much out there data-wise at all. They’re still completely just in the infancy phase in regards to being able to collect data. However, I personally use it very routinely for osteosarcomas and I combine it with chemotherapy. My currently three longest surviving patients were all treated with amputation, chemotherapy, and the Torigen autologous vaccine. Two of them are two years plus, and one three years plus.
00:15:48.300 –> 00:15:52.790
TRIPAWDS: Whoa! That’s great! Oh, my gosh!
Combining traditional chemotherapy and immunotherapy vaccines
00:15:52.790 –> 00:16:20.979
DR. COUTO: I also offer the EGFR vaccine, and if anybody came to me interested in ELIAS I am one hundred percent there to help get everything situated and started. I just can’t do the apheresis here–yet–but that’s kind of where my practice takes me right now.
00:16:21.940 –> 00:16:28.139
TRIPAWDS: What kind of chemotherapy are they getting? Are they getting the standard Carboplatin for osteosarcomas?
00:16:28.140 –> 00:16:36.050
DR. COUTO: I prefer six doses of carboplatin, so I give six doses. They are given every three-to-four weeks, and then I sprinkle the Torigen autologous vaccine series into the chemotherapy. So they usually get it about one week after the first three doses of chemotherapy, depending on exactly when the Torigen vaccine arrives at our facility.
For the EGFR vaccine, it’s also something that can be very comfortably combined with chemotherapy. I have several patients that have traveled up to Seattle during their chemotherapy course, and they can really get it at any point during the chemotherapy course. There’s not even like a specific day, or anything like that where it has to be accomplished.
00:17:11.220 –> 00:17:17.020
DR. COUTO: And then again, ELIAS are looking into how it can be safely and effectively combined with chemotherapy as well.
00:17:17.810 –> 00:17:23.699
TRIPAWDS: Oh, that’s neat! Now the EGFR vaccine, where did the research for that start
00:17:24.010 –> 00:17:24.990
DR. COUTO: At Yale.
00:17:25.250 –> 00:17:27.969
TRIPAWDS: So that that is the Yale vaccine we keep hearing about?.
00:17:27.970 –> 00:17:38.139
DR. COUTO: It is. I think sometimes it’s referred to as Theragen, as well. That might be what they start marketing it as but that is the Yale vaccine.
00:17:38.520 –> 00:17:51.179
TRIPAWDS: Okay, got it, thank you for explaining that. So this is really exciting! And when you’re presenting this information to a client, what are some of the factors they should consider? Because this is extra treatment, and a lot of people are already nervous about chemotherapy. What do you tell them when you’re laying out the options, how can they decide?
What is the goal of treatment for your Tripawd?
00:18:04.600 –> 00:18:33.670
DR. COUTO: I go into every osteo consult, I think big picture. That first goal is, are we going to go after this? Are we going to try to get this taken care of to the best of our ability, and provide the best overall prognosis? Or are we going to kind of downshift into a palliative protocol? Really focus on pain? That’s the first step. We need to figure out where we lie in regards to that. But if we do want to really go after this, then I discuss with my pet parents that the standard of care is always going to be amputation and four-to-six doses of carboplatin chemotherapy if osteosarcoma is confirmed.
00:18:48.590 –> 00:19:08.150
DR. COUTO: How I explain it is, “If you want us to fight and to do more, here are my options that are available to try to get a longer survival time. They are not proven by any means, yet to work in the large population of dogs with osteosarcoma.”
We are cautiously optimistic and hopeful that at some point, as we start giving more dogs these treatments, we really will start to understand what moves the needle and what doesn’t.
What if chemotherapy is not on the table?
00:19:21.650 –> 00:19:48.999
DR. COUTO: If it’s something that they are feeling financially comfortable about, I think that’s a big part as well. That’s the elephant in the room: it’s not cheap to treat a dog with osteosarcoma. But if finances are feeling somewhat comfortable for me, it’s kind of a no-brainer to try to add on either the EGFR Yale vaccine or the Torigen autologous vaccine series if we’re already kind of going down the path of amputation and chemotherapy.
00:19:49.300 –> 00:20:01.209
DR. COUTO: If people were interested in ELIAS I would say “There’s nothing that I’m seeing that would tell me that those would not be reasonable options.” But for me still, the best thing to do is the amputation and chemotherapy.
I would not personally utilize either the EGFR Yale Vaccine or the Torigen autologous vaccine series alone. I think the data is still not there to necessarily support that ELIAS is supposed to be in lieu of chemotherapy.
So if there are individual pet parents that are not interested in pursuing chemotherapy for A-B-C-D-E-F-G reasons, that would be a great path for them. Because the expected prognosis is similar to amputation with chemotherapy, if they’re close to a treating facility that can do that , nd are able to kind of go down that path.
But traditionally I still try to stick as much as I can to amputation and chemotherapy, and then, when I have the ability to add something in, I try to.
00:20:53.300 –> 00:20:59.409
TRIPAWDS: I love the way you lay out all of the different approaches, because everything you’re explaining. I’ve heard all kinds of viewpoints that reflect what your experience is. Where there’s certain people who are just really opposed to chemotherapy, but not so much when it comes to the new immunotherapies out there. I don’t know if it’s because they feel like it’s a more natural approach, but it’s good to know that they have options, too.
Mast Cell Tumors and Limb Sparing Innovations for Dogs
00:21:18.970 –> 00:21:35.400
TRIPAWDS: So what about mast cell cancers? We’re going to shift gears here a little bit because we get a lot of members who join us because their dog had a mast cell tumor in their leg, and the leg had to come off. What are the latest treatments for that? Has anything changed in the last few years?
00:21:36.330 –> 00:22:01.360
DR. COUTO: Yeah, I would say that there’s probably two main things that have changed. One is the addition of Stelfonta to our treatment arsenal, which is an intra-tumor injection for mast cell tumors. Admittedly, this is probably not necessarily a treatment that is going to save these pets that have these large mast cell tumors on their leg, for which the absolute only option is full limb amputation.
To even really try to do any form of treatment, there is a size limit on what we can treat with Stelfonta, it’s about three centimeters. That being said, when we do have one on the digit or farther down on the carpus or tarsus, and we’re just not feeling great about a surgical option, historically, in some cases veterinarians, oncologists will offer limb amputation because they can’t do anything to surgically close the area.
Stelfonta would be, in my opinion, an excellent option for those pets to try to save them from going down that path.
Shrinking mast cell tumors (instead of amputation) is always a first-line treatment recommendation
00:22:40.700 –> 00:22:59.819
DR. COUTO: Now, when we’re talking about like these actual, really gnarly large mast cell tumors, I mean, I think the main option in that setting, to try to save the limb is utilizing either some form of chemotherapy.
We have Palladia, we have CCNU or Lomastine, which are all fairly well-described for mast cell tumors, and have reasonable response rates, at least in the initial phase, to try to shrink down the tumor so that it then could become resectable. That is always an option.
00:23:14.250 –> 00:23:41.610
DR. COUTO: We also now have the addition of another immunotherapy, which is called Gilvetmab, which is a monoclonal antibody. That has been shown to have a very good response rate for mast cell tumors. And it is not a chemotherapy medication right now, I also have not utilized that in my clinic.
It’s a very expensive treatment. The actual drug itself is just highly expensive. At the current time, a lot of my patients here in Bend (t’s a very outdoorsy part of the world to be living) are large dogs. And for that reason they require a lot of drug, and it has been fairly cost prohibitive/ I’m still kind of trying to find the right pet to treat.
But Gilvetmab might also be another non-chemotherapy, but immunotherapy option to try to reduce the size of the tumor prior to getting them in for surgery, what is so-called “neoadjuvant treatment.”
So I think that you know, we’re either talking about Stelfonta treatment. Stelfonta has a seventy five percent response rate with one injection, which can go up to about eighty-five to ninety percent with the second injection. But the tumor has to be a certain size or smaller. Otherwise, we’re kind of talking about: either some type of neo-adjuvant chemotherapy immunotherapy to try to shrink down the tumor and see if we can get it small enough so that we can save the limb.
It’s always my goal to save a limb.
It’s been honestly a long time since I’ve sent a mast cell tumor patient in for an amputation. I kind of do everything that I can to prevent that. But in some cases you know that that is the main option to try to get them onto a path where they might have a reasonable prognosis. And so it it’s not that the decision in my hands is not taken lightly, but if it’s necessary, it is something that’s discussed.
00:25:10.020 –> 00:25:26.599
TRIPAWDS: We’re the club nobody wants to join, and we never ever want to see a dog lose a leg if they don’t have to. So when Stelfonta came out, I was so excited to hear about that. I wish you could work with tumors a little bit larger, but at least it’s there.
00:25:28.290 –> 00:25:47.919
DR. COUTO: Yeah, the problem with Stelfonta is, you get this very large wound, or you know, a wound at the site of the injection. And so if that wound becomes so large because the tumor was so large that could become a physically compromising problem. And there are some rare cases where Stelfonta patients will get these very large wounds and that can be a problem.
Saving the leg requires a rapid response
00:25:48.630 –> 00:25:54.939
TRIPAWDS: So the longer somebody waits to make any kind of decision about even getting information, the faster the tumor grows? And the less chance you have of actually saving the leg? Is that correct?
00:26:03.790 –> 00:26:05.059
DR. COUTO: I think that’s very correct.
00:26:05.060 –> 00:26:07.070
TRIPAWDS: Okay, so don’t wait everybody. If you’re listening to this because you’re just getting information right now. Don’t wait. Go see an oncologist. It’s something I wish we would have done with our Jerry, way way way back in 2006. We were not encouraged to go see an oncologist, and we didn’t. We got very lucky. He lived two years, but he was a fluke, it was a total fluke.
00:26:29.920 –> 00:26:42.809
TRIPAWDS: So now we have options, and I’m so excited that there are great oncologists like you helping us help our pets when cancer comes into the picture. Thank you so much for being here, I really appreciate it. Dr. Couto.
Yes, dogs can thrive on three legs!
00:26:43.200 –> 00:26:45.530
DR. COUTO: Of course, and I just want to say one more thing. To remember that (and this is actually an old adage from my dad), but dogs were really born with three legs and a spare. So if you are ever in a situation where you are faced with this, quite frankly, terrible decision, where you have to decide whether you’re interested in doing an amputation or not, for whatever type of cancer it happens to be, just remember that most dogs just thrive on three legs.
And the more that we work with these dogs, the more and more that we’ll know how to help them be their best self on three legs.
00:27:23.090 –> 00:27:30.280
TRIPAWDS: Oh, thank you, I love that! I love that things have gotten so much better for amputee dogs and cats too! All thanks to you, your dad, your brother … thank you so much for all your hard work. And hopefully we’ll talk to you again sometime soon, thank you so much.
00:27:41.170 –> 00:27:42.380
DR. COUTO: Thank you.